POS1605 A PROOF-OF-CONCEPT STUDY EVALUATING THE USE OF FUNCTIONAL BRAIN MAGNETIC RESONANCE IMAGING IN ASSESSING TREATMENT RESPONSE IN PSORIATIC ARTHRITIS PATIENTS
Authors: E. Espartal, X. Michelena, S. Marsal, A. Rovira, D. Pareto, A. Erra
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Inflammatory cytokines can alter the way the central nervous system processes pain as shown in patients with rheumatoid arthritis [Rech et al., 2013]. However, the relationship between TNFα inhibition and pain processing in individuals with psoriatic arthritis (PsA) has not been investigated. <h3>Objectives</h3> To assess the feasibility of functional magnetic resonance imaging (fMRI) paradigm to estimate the respone to pain and the effect of treatment in PsA patients (pts). <h3>Methods</h3> 6 pts with active PsA eligible to start a TNFi were included: 3 were naïve to biological disease modifying anti-rheumatic drugs and 3 were experienced. Four healthy subjects (HS) were also included. Subjects were scanned in a 3.0T scanner at baseline (BL) and week 1 (W1) after starting treatment. Each acquisition included 2 fMRI runs. The physician selected a swollen and tender joint (affected joint) and a control joint in the contralateral hand (non-affected joint). First, the brain pain response was investigated pressing the non-affected joint followed by the affected joint. The fMRI effect of pressure was represented for each subject individually, for each time point (p&lt;0.0001 uncorrected level, minimum extension 10 voxels). We provided a descriptive analysis of the differences in PsA pts brain response between BL and W1 and the clinical response evaluated by the percentage of improvement of Disease Activity in Psoriatic Arthritis (DAPSA) score and visual analogue scale pain (VASp) change. <h3>Results</h3> All subject's demographic characteristic and PsA patients' clinical response are shown in Table 1. Brain response to pressure in HS produced activation in the sensory motor cortex, with more or less involvement of additional areas in the prefrontal, parietal and temporal cortex. In PsA pts with a higher treatment response (PsA 1, 2, 5), the brain response to pressure did not show any activation at BL whilst sensory motor cortex activation was seen at W1, with amygdala and insula activation in pts PsA 2 and 5 and prefrontal and frontal activity in pts PsA 1 and 2. In those with less response (PsA 3, 4, 6), the sensory motor cortex was activated at BL with little changes when evaluated at W1 (Figure 1). No evident differences in brain response activation were observed between naïve and TNFi experienced patients. <h3>Conclusion</h3> The proposed fMRI paradigm seems to be a promising candidate to predict response to treatment with TNF inhibitors in PsA patients. Studies with more patients are needed to confirm our preliminary results. <h3>Reference</h3> [1]Rech J et al. Association of brain functional magnetic resonance activity with response to tumour necrosis factor inhibition in rheumatoid arthritis. Arthritis Rheum. 2013 Feb;65(2):325-33. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Esther Espartal Grant/research support from: This abstract/project is sponsored by Pfizer, Xabier Michelena Grant/research support from: This abstract/project is sponsored by Pfizer, Sara Marsal Grant/research support from: This abstract/project is sponsored by Pfizer, Alex Rovira Grant/research support from: This abstract/project is sponsored by Pfizer, Deborah Pareto Grant/research support from: This abstract/project is sponsored by Pfizer, Alba Erra Grant/research support from: This abstract/project is sponsored by Pfizer.